1. Field of the Invention
This invention relates to the cooling of turbomachinery vane or blade platforms or shrouds and more particularly to apparatus in which the platform is cooled by a combination of film, convection and impingement cooling and wherein discrete sections of the platform are provided with cooling mechanisms particularly suited to the cooling requirements of that discrete platform section.
2. Description of the Prior Art
In the vane or blade platform cooling art, many attempts have been made to adequately cool the platforms of vanes or blades, which are subjected to ever increasing temperatures as the power generated by turbomachinery increases with technological advances. Bluck U.S. Pat. No. 3,066,910 passes coolant through passages in the blade platform but this is a utilization of convection cooling only. Howard U.S. Pat. No. 3,527,543 discharges cooling air along the surface of a vane platform but this teaching utilizes film cooling only. French U.S. Pat. No. 1,214,618, which was published on Apr. 11, 1960, passes cooling air through passages adjacent the vane platform but this is a utilization of convection cooling only. Other patents such as U.S. Pat. Nos. 3,656,863; 3,318,573; 3,290,004; 2,828,940; 3,446,480; 3,446,482; and 3,446,481 all attempt to cool vane or blade platforms but none use the structure and combination of cooling principles taught herein.